Clay testing apparatus



Oct. 27,1936 i D H, ROWLAND. wwmlef CLAY TESTING APPARATUS FiledDecf'QQ, 1932 2 Sheets-Sheet 1 zisheets-sheet 2 Filed Dec. 20, 1932 JulINVENTOR Patented Oct. 27, 1936 CLAY TESTING APPARATUS Davidge H.Rowland, Baltimore, Md., assignor to Locke Insulator Corporation,Baltimore, Md., a corporation of Maryland Application December 20, 1932,Serial No. 648,114

4 Claims.

The invention relates to the determination of the plasticity of clayintended for the production of ceramic ware, such for instance asporcelain insulators or the like, though not confined to such use, andhas for its general object the provision of an apparatus whereby samplechunks or billets of clay taken from a pug mill may be readily tested asto plasticity or stiffness.

It is well known that the efficiency of pug mills and plunging machinesfor shaping insulators and other porcelain ware depends to a greatextent upon the hardness of the clay which is furnished to them.Variations in this factor will greatly affect the uniformity of theproduct as regards shrinkage and drying losses. It is consequently ofgreat importance to have complete knowledge of the condition of the clayso that it will be possible to supervise the filter presses whichperform part of the preliminary clay treatment so as to obtain a muchmore uniform product. It is with these facts in view that I have devisedthe present invention which has for an important object the provision ofa machine into which may be place-d at appropriate intervals samplechunks or billets taken from the preliminary pug mill, the machineembodying means for making a record of the hardness of the clay so thatby this means an almost continuous recording may be brought about sothat the attendants will be at 30 all times apprised of conditions andmay make whatever changes, if any, are needed in the treating steps.

Another object of the invention is to provide a machine for this purposeby means of which a 35 pressure may be applied to a succession of samplechunks of uniform size and the resulting pressure which is transmittedthrough the chunks is recorded as a measure of the extent ofcompression, flattening or distortion of the chunks.

A more specific object is to provide a machine of this character whichis power operated and 1 which will automatically stop after a force hasbeen applied to a suitable chunk of material to be tested so that theconditions for all may be made the same.

An additional object is to provide a device for this purpose which willbe simple and inexpensive to make, easy to assemble, use and control,positive in action, efficient and durable in service, and a generalimprovement in the art.

To the attainment of the foregoing and other objects and advantages, theinvention preferably consists in the details of construction and thearrangement and combination of parts to be hereinafter more fullydescribed and claimed, and

illustrated in the accompanying drawings in which: a

Figure 1 is a front elevation of a machine constructed in accordancewith the invention,

Figure 2 is an elevation taken at right angles to Figure 1,

Figure 3 is a fragmentary plan View with the recorder omitted,

Figure 4 is a detail section through a valve mechanism forming part ofthe device.

Referring more particularly to the drawings I have shown the device ascomprising an appropriate stationary support here represented asincluding a base ill from which rise standards II and I2, the formerterminating at its upper end in a bearing l3 and the latter being formedwith a bearing M. J ournaled through these bearings is a shaft l5adapted to be driven by means to be described and provided with a crankor eccentric portion [5 engaged within a pitman [6.

Near its upper end the standard [2 is provided with bearings l1 and i8and at its intermediate portion with other bearings l9 and 20, thebearings l1, l8, l9 and 20 being in vertical alinement or axialrelation. Mounted within the hearing I 8 is a rod 2| provided at itslower end with a disk 22 which may be described as constituting ananvil. The rod 2| is slidable through the bearing l8 and has its upperend appropriately connected with a member 23 depending from or adaptedto react against the underside of a wafer 24 which, as is known in theart, ordinarily comprises a pair of diaphragms connected at their edgesand defining a compressible chamber. It is intended that this wafercontain liquid under a certain predetermined pressure, the interiorcommunicating through a tube 25 with a register or recorder indicated at26. No details of this device are given for the reason that such of thepressure operated type are common and well known in the art involvingsystems where the degree of pressure need be known.

The actual details regarding the connection of the wafer with theregister or recorder are probably more or less immaterial. NeverthelessI have shown a bushing 21 fitting within the lower end of the bearing I1and abutting against the top of the wafer, a vertically elongated body28 being suitably secured, as by screwing, axially through this bushing.The body is represented as having an enlarged intermediate portion 29providing a shorter bearing on a washer 30 engaged against the top ofthe bearing member IT. The body 28 is disclosed as having a central oraxial passage 3| communicating with the interior of the wafer and with aslightly enlarged chamber 32 at the upper end of the body, a transverseport 33 being provided in the enlarged portion 29 and intersecting thepassage 3I. The above mentioned tube 25 is fastened in the port 33. Itis desirable that the liquid in the system be placed under appropriatepressure and for this reason the upper end of the body 28 is shown ashaving a reduced externally threaded portion 34 onto which may bescrewed the nipple of a suitable compression pump. Located within thechamber 32 and secured within the upper end portion 34 is a valveassembly indicated as a whole by the numeral 35 but not described indetail as it may be identically the same as the well known Schroedervalve used in the inflation stems or tubes of pneumatic tires and thelike. By connecting the pump to the threaded extension 34 liquid may beintroduced into the recording and wafer system and placed under anydesired pressure.

Slidable through the bearings I9 and 28 is a vertically movable rod orplunger 36 equipped at its upper end with a head 31 upon which isintended to be placed the sample of clay to be tested. At its lower endthe plunger 36 is represented as forked and pivotally connected at 38with the pitman I6 on the shaft I5.

The means for rotating the shaft I5 whereby the resultant movement ofthe crank arm will reciprocate the plunger 36, is here represented ascomprising a worm wheel 39 carried by the shaft I5 and meshing with aworm 40 on the shaft M of an electric motor 42 mounted on supports 43rising from the base I6. Obviously when the motor is energized therotation of the worm 49 will cause the worm wheel 39 to be rotated.

In order that the extent of rotation of the shaft I5, and consequentlythe upward movement of the plunger 36, may be automatically controlledor made uniform for every test, I provide an automatic circuit breakerfor the motor circuit here represented as comprising a stationarycontact 44 and a flexible movable contact 45 carried by a bracket 46 andinsulated therefrom and from each other as by blocks 41. The contact 45is normally divergent with respect to the contact 44 and carries aprojection 48 engaged by the periphery of a disk 49 secured on the shaftI5, this engagement maintaining the contact 45 in engagement with thecontact 44 so that the motor circuit will be complete. However, the disk49 is formed with a notch 59 which the projection 48 is adapted toenter, after the shaft I5 has made one complete revolution and theplunger 36 has completed its upward stroke, the arrangement beingclearly such that when the projection enters the recess or notch thecontact 45 will spring away from the contact 44 and open the motorcircuit.

In the use of the device, assuming that the plunger 36 is at thelowermost limit of its movement, the operator places upon the plungerhead 31 the sample of clay to be tested. The operator then moves thecontact 45 manually into engagement with the contact 44 as shown inFigure 2 for closing the motor circuit. The rotation of the motor shaft4| and worm 40 thereon will then cause rotation of the worm wheel 39,shaft I5 and disk 49. Just as soon as the disk moves a slight part of aturn its edge will engage the projection 48 and maintain the contact 45in engagement with the contact 44 until the shaft can make a completeturn and the notch 50 again registers with the projection 48. As theshaft I5 rotates the eccentrically driven pitman l6 will move upwardly,thereby forcing the plunger 36 and head 31 upwardly and compressing theclay sample against the disk 22 which, together with the rod 2|, will beforced upwardly and apply pressure to the wafer 24. The consequentcompression of the wafer will cause the liquid in the recording systemto operate the recorder 26 in a well known manner. Of course the plunger36 is moved upwardly to its maximum extent during the first halfrevolution of the shaft I5 and then recedes from the disk 22 during thelatter half of the revolution so that when one rotation of the shaft hasbeen completed the parts will be all restored to their initial positionready for testing the next clay sample or specimen. In the actualcarrying out of a testing system embodying the use of my device testpieces or chunks of uniform size are taken from the pug mill at frequentintervals and the test made with regularity and with suflicientfrequency to obtain a practically continuous reading on the recorder.The plasticity or the stiffness or hardness of the clay may thus bedetermined at any time so that the attendant in charge may know whatconditions are and whether or not any changes should be made in thepreliminary treatment of the clay.

From the foregoing description and a study of the drawings it will beapparent that I have thus provided a very simple and inexpensive machinefor the purpose specified which will greatly facilitate the maintenanceof efficiency in the preparation and handling of clay intended for usein the manufacture of ceramic ware. It is believed that theconstruction, operation and advantages will be readily apparent to oneskilled in the art without further explanation.

While I have shown and described the preferred embodiment of theinvention, it should be understood that the disclosure is merely anexemplification of the principles involved as the right is reserved tomake all such changes in the details of construction as will widen thefield of utility and increase the adaptability of the device providedsuch changes constitute no departure from the spirit of the invention orthe scope of the claims hereunto appended.

Having thus described the invention, I claim:

1. A machine for testing the plasticity of a sample of material,comprising axially arranged slidably mounted relatively movable memberscarrying heads adapted to have the sample interposed between them forcompression thereby, a compressible wafer containing fluid underpressure and arranged for compression by longitudinal movement of one ofsaid members, a pressure gauge connected with said wafer, there being acheck valved passage communicating with said wafer enabling fluid underselected pressure to be introduced within the wafer, a shaft arranged atright angles to the axis of said members and having a crank, a pitmanrevolubly engaged within the crank and pivotally connected with theother of said members, an electric motor for rotating said shaft, acircuit breaker interposed in the motor circuit, and means operated byrotation of said shaft for breaking the circuit when the shaft has madeone complete revolution.

2. A machine for testing the plasticity of a sample of material,comprising a base, an upright rising from the base and provided with aplurality of laterally extending arms, upper and lower axially arrangedmembers slidable through certain of said arms and movable relatively,heads on the adjacent ends of said members adapted to have the sampleinterposed between them for compression thereby, a compressible wafermounted beneath the uppermost arm, a gauge connected withsaid wafer,said wafer being compressingly engaged by the upper end of the upperslidable member, bearings carried by the base, a horizontal shaftjournaled through said bearings and formed with a crank, a pitmanconnected with said crank and pivotally connected with the lower end ofthe lower slid'able member, an electric motor mounted on the base andhaving a gear connection with said shaft, a circuit breaker mounted onthe base and including a. fixed contact and a movable spring contactequipped with a projection, and a disk carried by and rotatable withsaid shaft and having a notch in its periphery for receiving saidprojection and thereby breaking the motor circuit when said shaft hasmade a complete revolution.

3. A machine for testing the plasticity of a sample of material,comprising axially arranged slidably mounted relatively movable memberscarrying heads adapted to have the sample interposed between them forcompression thereby, means for moving said members relatively, acompressible wafer engageable by one of said members for compressionthereby, a body member in engagement with said wafer and having alongitudinal bore communicating with the interior thereof and having acounterbore defining a valve seat and further having a lateral passagelocated between the valve seat and the wafer, a pressure gauge connectedwith said lateral passage for indicating the pressure within the wafer,and an inwardly opening spring pressed check valve normally closing saidvalve seat and openable upon the application of fluid pressure throughsaid bore into the wafer whereby the initial pressure within the lattermay be varied.

4. A machine for testing the plasticity of a sample of material,comprising axially arranged slidably mounted relatively movable memberscarrying heads adapted to have the sample interposed between them forcompression thereby, a compressible wafer containing fluid underpressure arranged for compression by longitudinal movement of one ofsaid members, there being a bore communicating with said wafer, a checkvalve located within said bore whereby fluid under a selected pressuremay be introduced within the wafer, a pressure gage, a connectionbetween the pressure gage and said bore between said check valve and thewafer, rotary means connected with the other of said members for movingthe same longitudinally with respect to the first named member, andmeans for automatically stopping the movement of said rotary means afterone revolution thereof.

DAVIDGE H. ROWLAND.

